Vyvanse is solely approved in the United States to treat ADHD, and no drug has been approved to curb binge-eating disorder.

Binge-eating — only recently recognized by the psychiatric community as a distinct disorder — is characterized by recurrent episodes of excessive food consumption accompanied by a sense of loss of control and psychological distress, the study authors noted. It is also associated with obesity.

"Right now the most commonly used medications are epilepsy drugs," said study co-author James Mitchell, MD, president of the Neuropsychiatric Research Institute in Fargo, North Dakota. "And they do help patients to eat well and cut down on weight," he added.

"However, their side effect profiles are not great, with their impact on cognitive [mental] impairment in particular making them difficult for many patients to tolerate," Mitchell said.

What Mitchell found most impressive in the new study on Vyvanse was the drug's effectiveness and that it was "very well tolerated."

The 14-week study, reported in the online edition of JAMA Psychiatry, was funded by Shire Development, LLC, the manufacturer of Vyvanse.